Application of the Center Cable Pipe for Directional Drilling in Coal Mine

Abstract:

According to the requirements of the strength and MWD communication to the drill pipe for the directional drilling technology, center cable drill pipe is used to realize real-time MWD signal transmission; and the high strength pipe, special screw thread structure, friction welding technology are adopted to improve the tensile, compression, bending and torsional strength of pipe. The necessary solutions are introduced based on the existing problems in field operation. MWD examples in Dafosi mine, comb hole examples in Zhuxianzhuang mine and directional drilling examples in Hashatu mine respectively prove that the center cable drill pipe can meet the requirements of measuring communication and strength with the maximum hole depth of 1200m, the directional drilling with minimum bending radius of 54m and directional drilling in coal seam with inclined angle of 58.